The present invention relates to plates for fixation of bones and joints. More specifically, the invention pertains to a fixation plate configured for fixation of the mid-foot.
Trauma to the mid-foot often results in severe fractures and/or dislocations. One such trauma is the well-known Lisfranc injury, which was named after the French doctor who first described the injury during the Napoleonic Wars. The injury identified by Dr. Lisfranc occurred when a horseman fell from the horse with his/her foot caught in the stirrup. The resulting trauma was a fracture of multiple bones of the mid-foot with dislocation of the fragments. In modern times, a Lisfranc injury indicates an injury to the normal alignment of the cuneiforms and metatarsal joints with the loss of their normal spatial relationships. Injuries of this type may occur when a heavy item falls on the mid-foot or from stepping into a small hole and then falling with a twisting imparted to the foot. Athletic injuries are common with sports involving foot bindings, such as windsurfing or snow boarding, or sports where the foot is rotated during impact, such as dancing and soccer.
The most common Lisfranc injury occurs at the joint involving the 1st and 2nd metatarsals and the medial cuneiform, primarily because there is no connective tissue holding the first and second metatarsals to each other. If the ligaments between the medial and mid-cuneiforms are disrupted, or between the 1st, 2nd metatarsal and the medial cuneiform, then the bones separate and the normal alignment of the joints is lost. Failure to treat a significant Lisfranc injury may result in joint degeneration and even damage to the adjacent nerves and blood vessels.
Treatment of injuries of this type is usually surgical, especially if a significant separation of the bones exists. One surgical treatment, known as open reduction and internal fixation, usually requires that pins, wires and/or screws be inserted to stabilize the bones and joints and hold them in place until healing is complete. This treatment protocol re-establishes the normal anatomy of the mid-foot while the fractured bones mend. In one typical procedure, a pin or screw is introduced medially into the internal cuneiform and through the base of the second metatarsal bone.
In some cases, fusion of the joint between the first and second metatarsals and the middle and/or internal cuneiforms may be necessary. Arthrodesis may be indicated where arthritis arises in patients with a prior Lisfranc or similar injury, or where an acute fracture/dislocation has occurred anywhere at the mid-foot.
The use of pins, staples or screws is often acceptable for younger patients, especially where the injury is not too severe. However, this form of fixation frequently results in non-union in mid-foot arthrodesis attempts, possibly because the bone fragments and/or joints cannot be sufficiently immobilized by pins, screws or staples alone. Consequently, there is a significant need for a fixation device that provides solid fixation and stabilization of a mid-foot injury. Broad treatment possibilities also requires that the fixation device be capable of multiple points of attachment to the mid-foot bones and bone fragments.